1. Field of the Invention
This invention relates to a shield connector which is directly mountable on equipment, for example, on an electrically-conductive casing of an on-vehicle equipment by screws. Such the shield connector is generally referred hereinafter to xe2x80x9cdirect-mounting shield connectorxe2x80x9d.
The present invention is based on Japanese Patent Application No. 2001-119757, which is incorporated herein by reference.
2. Related Art
FIGS. 8 and 9 show conventional direct-mounting shield connectors, respectively.
The direct-mounting shield connector 1, shown in FIG. 8, is disclosed in JP-U-6-58560, and this connector comprises a metal shell 5, having a cylindrical portion 5a for connection to a shielding portion 3a of a shielded wire 3, and a grounding flange portion 5b, and a connector housing 7 made of an insulative resin.
The connector housing 7 includes a housing body 11, which fits on and holds a connection terminal 9, connected to a conductor 3b of the shielded wire 3, and has the cylindrical portion 5a of the metal shell 5 embedded therein, and a mounting flange 12 which extends outwardly from an outer surface of the housing body 11 for screwing purposes.
A front end portion of the housing body 11 is passed through a connector passage hole 14a, formed through a connector mounting wall 14 of an equipment, and the mounting flange 12, abutted against the connector mounting wall 14, is fastened to this connector mounting wall by screws 16, thus fixedly securing the connector housing 7 to the connector mounting wall 14.
The metal shell 5 is fitted and held on the connector housing 7, and in this condition a rear end portion of the cylindrical portion 5a is electrically connected to the shielding portion 3a via a connection member 17, and the cylindrical portion 5a is embedded in the housing body 11.
The grounding flange portion 5b of the meta shell 5 is mated with that surface of the mounting flange 12 which is to be opposed to the connector mounting wall 14, and when the mounting flange portion 12 is screwed, the grounding flange portion 5b is electrically connected to the connector mounting wall 14.
As shown in FIG. 9, the direct-mounting shield connector, which is disclosed in JP-A-2000-48912, comprises a connector housing 23, which receives and holds a connection terminal 22 connected to a shielded wire, and a metal shell 25 which is separate from the connector housing, and is electrically connected to a shielding portion of the shielded wire. The connector housing 23 and the metal shell 25 are fastened together by screw members 27, with a connector mounting wall 26 of an equipment interposed therebetween, and by doing so, the connector housing 23 is fixedly secured to the connector mounting wall 26, and at the same time mounting piece portions 25a of the metal shell 25 are electrically connected to the connector mounting wall 26.
With respect to the connector housing 23, when a terminal receiving portion 23a is passed through a connector passage hole 26a formed through the connector mounting wall 26, the screw members 27, inserted in a mounting flange 23b, pass respectively through collar insertion holes 26b formed through the connector mounting wall 26.
However, in the direct-mounting shield connector 1 shown in FIG. 8, the mounting flange 12, made of the resin, is fastened to the connector mounting wall 14 by the screws, and the grounding flange portion 5b of the metal shell 5 is brought into contact with the connector mounting wall 14 of the equipment by a pressing force produced by the mounting flange 12. Thus, the grounding flange portion is not directly fastened to the connector mounting wall by the screws, and therefore it is difficult to achieve the firm electrical connection therebetween, and there has been encountered a problem that electrical connection characteristics of the grounding contact are liable to become unstable by a thermal shock, caused by heat generated in a vehicle on which the equipment is mounted, vibrations and others.
In the direct-mounting shield connector 21 shown in FIG. 9, the screw members 27 are passed respectively through the mounting piece portions 25a of the metal shell 25, and therefore fastening forces of the screw members 27 act directly on the mounting piece portions 25a, so that the firm electrical connection can be achieved. However, the connector housing 23 and the metal shell 25 are separate from each other, and therefore the connector housing 23 and the metal shell 25 are supported separately in predetermined positions, respectively, with the connector mounting wall 26 interposed therebetween, and in this condition the fastening operation must be carried out by the screw members 27, and therefore there has been encountered a problem that the efficiency of the mounting operation is low.
This invention has been made under the above circumstances, and an object of the invention is to provide a direct-mounting shield connector in which a metal shell can be so firmly electrically connected to a connector mounting wall that this electrical connection will not become unstable by a thermal shock, caused by heat generated in a vehicle, vibrations and others, and besides a connector housing and the metal shell can be mounted on the connector mounting wall from one side of the connector mounting wall so that the mounting operation can be carried out easily.
The above object has been achieved by a shield connector directly-mountable on an equipment comprising: a mounting flange provided in a connector housing and attachable to a mounting wall of the equipment by screwing; a metal shell having a cylindrical portion and a grounding flange portion which is clamped between the mounting flange and the mounting wall to thereby electrically connected to the mounting wall and on which a screw engagement hole for inserting a screw is formed; a collar fittingly inserted into a collar insertion hole formed on the mounting flange; wherein an end surface of the collar is brought into abutment with the grounding flange at a peripheral edge portion of the screw engagement hole, and the collar presses the grounding flange portion against the mounting wall when the screw passed through the collar is fastened.
In the above construction, when the connector housing is fastened to the mounting wall by the screws, the axial fastening force of each screw serves as a force to press the grounding flange portion, formed on the metal shell, against the mounting wall through the collar fitted in the collar insertion hole in the mounting flange of the connector housing.
Namely, the fastening force of each screw for fastening the connector housing to the mounting wall serves as a force to contact the grounding flange portion with the mounting wall, and acts directly on the grounding flange portion of the metal shell.
And besides, the metal shell is fitted in the connector housing, and is joined thereto in a unitary manner, and therefore the connector housing and the metal shell can be mounted on the mounting wall from one side of the mounting wall.
Preferably, in the shield connector of the above construction, the collar may include a collar cylindrical portion and an inner diameter of the screw engagement hole may be set to be larger than an inner diameter of the collar cylindrical portion and smaller than an outer diameter of the collar cylindrical portion.